| 1. |
- Grimberg, Åsa, et al.
(författare)
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Transitions in wheat endosperm metabolism upon transcriptional induction of oil accumulation by oat endosperm WRINKLED1
- 2020
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Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Background Cereal grains, including wheat (Triticum aestivum L.), are major sources of food and feed, with wheat being dominant in temperate zones. These end uses exploit the storage reserves in the starchy endosperm of the grain, with starch being the major storage component in most cereal species. However, oats (Avena sativa L.) differs in that the starchy endosperm stores significant amounts of oil. Understanding the control of carbon allocation between groups of storage compounds, such as starch and oil, is therefore important for understanding the composition and hence end use quality of cereals. WRINKLED1 is a transcription factor known to induce triacylglycerol (TAG; oil) accumulation in several plant storage tissues. Results An oat endosperm homolog of WRI1 (AsWRI1) expressed from the endosperm-specific HMW1Dx5 promoter resulted in drastic changes in carbon allocation in wheat grains, with reduced seed weight and a wrinkled seed phenotype. The starch content of mature grain endosperms of AsWRI1-wheat was reduced compared to controls (from 62 to 22% by dry weight (dw)), TAG was increased by up to nine-fold (from 0.7 to 6.4% oil by dw) and sucrose from 1.5 to 10% by dw. Expression of AsWRI1 in wheat grains also resulted in multiple layers of elongated peripheral aleurone cells. RNA-sequencing, lipid analyses, and pulse-chase experiments using C-14-sucrose indicated that futile cycling of fatty acids could be a limitation for oil accumulation. Conclusions Our data show that expression of oat endosperm WRI1 in the wheat endosperm results in changes in metabolism which could underpin the application of biotechnology to manipulate grain composition. In particular, the striking effect on starch synthesis in the wheat endosperm indicates that an important indirect role of WRI1 is to divert carbon allocation away from starch biosynthesis in plant storage tissues that accumulate oil.
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| 2. |
- Schepke, Elizabeth, et al.
(författare)
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DNA methylation profiling improves routine diagnosis of paediatric central nervous system tumours: A prospective population-based study
- 2022
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846 .- 1365-2990. ; 48:6
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Paediatric brain tumours are rare, and establishing a precise diagnosis can be challenging. Analysis of DNA methylation profiles has been shown to be a reliable method to classify central nervous system (CNS) tumours with high accuracy. We aimed to prospectively analyse CNS tumours diagnosed in Sweden, to assess the clinical impact of adding DNA methylation-based classification to standard paediatric brain tumour diagnostics in an unselected cohort. Methods: All CNS tumours diagnosed in children (0-18 years) during 2017-2020 were eligible for inclusion provided sufficient tumour material was available. Tumours were analysed using genome-wide DNA methylation profiling and classified by the MNP brain tumour classifier. The initial histopathological diagnosis was compared with the DNA methylation-based classification. For incongruent results, a blinded re-evaluation was performed by an experienced neuropathologist. Results: Two hundred forty tumours with a histopathology-based diagnosis were profiled. A high-confidence methylation score of 0.84 or more was reached in 78% of the cases. In 69%, the histopathological diagnosis was confirmed, and for some of these also refined, 6% were incongruent, and the re-evaluation favoured the methylation-based classification. In the remaining 3% of cases, the methylation class was non-contributory. The change in diagnosis would have had a direct impact on the clinical management in 5% of all patients. Conclusions: Integrating DNA methylation-based tumour classification into routine clinical analysis improves diagnostics and provides molecular information that is important for treatment decisions. The results from methylation profiling should be interpreted in the context of clinical and histopathological information.
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| 3. |
- Snell, Per, et al.
(författare)
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Characterisation of Grains and Flour Fractions from Field Grown Transgenic Oil-Accumulating Wheat Expressing Oat WRI1
- 2022
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Ingår i: Plants. - : MDPI AG. - 2223-7747. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Wheat (Triticum aestivum L.) is one of the major staple crops in the world and is used to prepare a range of foods. The development of new varieties with wider variation in grain composition could broaden their use. We characterized grains and flours from oil-accumulating transgenic wheat expressing the oat (Avena sativa L.) endosperm WRINKLED1 (AsWRI1) grown under field conditions. Lipid and starch accumulation was determined in developing caryopses of AsWRI1-wheat and X-ray microtomography was used to study grain morphology. The developing caryopses of AsWRI1-wheat grains had increased triacylglycerol content and decreased starch content compared to the control. Mature AsWRI1-wheat grains also had reduced weight, were wrinkled and had a shrunken endosperm and X-ray tomography revealed that the proportion of endosperm was decreased while that of the aleurone was increased. Grains were milled to produce two white flours and one bran fraction. Mineral and lipid analyses showed that the flour fractions from the AsWRI1-wheat were contaminated with bran, due to the effects of the changed morphology on milling. This study gives a detailed analysis of grains from field grown transgenic wheat that expresses a gene that plays a central regulatory role in carbon allocation and significantly affects grain composition.
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| 4. |
- Snell, Per, et al.
(författare)
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WRINKLED1 Is Subject to Evolutionary Conserved Negative Autoregulation
- 2019
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- High accumulation of storage compounds such as oil and starch are economically important traits of most agricultural crops. The genetic network determining storage compounds composition in crops has been the target of many biotechnological endeavors. Especially WRINKLED1 (WRI1), a well-known key transcription factor involved in the allocation of carbon into oil, has attracted much interest. Here we investigate the presence of an autoregulatory system involving WRI1 through transient expression in Nicotiana benthamiana leaves. Different lengths of the Arabidopsis WRI1 promotor region were coupled to a GUS reporter gene and the activity was measured when combined with constitutive expression of different WRI1 homologs from Arabidopsis thaliana, oat (Avena sativa L.), yellow nutsedge (Cyperus esculentus L.), and potato (Solanum tuberosum L.). We could show that increasing levels of each WRI1 homolog reduced the transcriptional activity of the Arabidopsis WRI1 upstream region. Through structural analysis and domain swapping between oat and Arabidopsis WRI1, we were able to determine that the negative autoregulation was clearly dependent on the DNA-binding AP2-domains. A DNA/protein interaction assay showed that AtWRI1 is unable to bind to its corresponding upstream region indicating non-direct interaction in vivo. Taken together, our results demonstrate a negative feedback loop of WRI1 expression and that it is an indirect interaction most likely caused by downstream targets of WRI1. We also show that it is possible to release WRI1 expression from this autoregulation by creating semi-synthetic WRI1 homologs increasing the potential use of WRI1 in biotechnological applications.
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| 5. |
- Andersson, Mariette, et al.
(författare)
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An alternative pathway to plant cold tolerance in the absence of vacuolar invertase activity
- 2023
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Ingår i: Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 113, s. 327-341
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Tidskriftsartikel (refereegranskat)abstract
- To cope with cold stress, plants have developed antioxidation strategies combined with osmoprotection by sugars. In potato (Solanum tuberosum) tubers, which are swollen stems, exposure to cold stress induces starch degradation and sucrose synthesis. Vacuolar acid invertase (VInv) activity is a significant part of the cold-induced sweetening (CIS) response, by rapidly cleaving sucrose into hexoses and increasing osmoprotection. To discover alternative plant tissue pathways for coping with cold stress, we produced VInv-knockout lines in two cultivars. Genome editing of VInv in 'Desiree' and 'Brooke' was done using stable and transient expression of CRISPR/Cas9 components, respectively. After storage at 4 degrees C, sugar analysis indicated that the knockout lines showed low levels of CIS and maintained low acid invertase activity in storage. Surprisingly, the tuber parenchyma of vinv lines exhibited significantly reduced lipid peroxidation and reduced H2O2 levels. Furthermore, whole plants of vinv lines exposed to cold stress without irrigation showed normal vigor, in contrast to WT plants, which wilted. Transcriptome analysis of vinv lines revealed upregulation of an osmoprotectant pathway and ethylene-related genes during cold temperature exposure. Accordingly, higher expression of antioxidant-related genes was detected after exposure to short and long cold storage. Sugar measurements showed an elevation of an alternative pathway in the absence of VInv activity, raising the raffinose pathway with increasing levels of myo-inositol content as a cold tolerance response.
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| 6. |
- Andersson, Mariette, et al.
(författare)
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Comparative potato genome editing: Agrobacterium tumefaciens-mediated transformation and protoplasts transfection delivery of CRISPR/Cas9 components directed to StPPO2 gene
- 2021
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Ingår i: Plant Cell, Tissue and Organ Culture. - : Springer Science and Business Media LLC. - 0167-6857 .- 1573-5044. ; 145, s. 291-305
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Tidskriftsartikel (refereegranskat)abstract
- Key message We compared the StPPO2 gene editing outcomes and efficiencies through Agrobacterium-mediated transformation and protoplasts transfection with DNA or RNPs, and demonstrated that genome editing efficiency depends on the CRISPR/Cas9 delivery approach in potato.Delivery of the CRISPR/Cas9 components to the plant cells is a key step in its application as a genome editing tool. Here, we compared Agrobacterium-mediated transformation and protoplast transfection with CRISPR/Cas9 components for potato genome editing. Two sgRNAs were designed to simultaneously direct Cas9 to the StPPO2 gene encoding for a tuber polyphenol oxidase (PPO). A binary vector (CR-PPO) was utilized for either Agrobacterium-mediated transformation or for transient expression in protoplasts, while ribonucleoprotein complexes (RNP-PPO) were additionally assayed in protoplasts. Editing efficiency varied, yielding 9.6%, 18.4% and 31.9% of edited lines from Agrobacterium-mediated transformation, RNP-PPO and CR-PPO transient expression in protoplasts, respectively. Furthermore, only the CR-PPO transient expression resulted in lines edited in all four StPPO2 alleles, observed in 46% of the edited lines and confirmed by tuber PPO activity and enzymatic browning analysis. Lines with on-target DNA insertions were found from all three approaches and characterized by sequencing. The dual-sgRNA strategy resulted in a low incidence of the targeted deletion, likely due to contrasting efficiencies between sgRNAs, that was partially evident in the in silico analysis. Our results demonstrate that gene editing efficiency in potato depends on the CRISPR/Cas9 delivery strategy and provide insights to consider when selecting the appropriate methodology.
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| 7. |
- Andersson, Mariette, et al.
(författare)
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CRISPR/Cas9 Technology for Potato Functional Genomics and Breeding
- 2023
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Ingår i: Plant Genome Engineering : Methods and Protocols. - New York, NY : Springer US. - 9781071631300 ; :2653, s. 333–361-
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Cultivated potato (Solanum tuberosum L.) is one of the most important staple food crops worldwide. Its tetraploid and highly heterozygous nature poses a great challenge to its basic research and trait improvement through traditional mutagenesis and/or crossbreeding. The establishment of the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) as a gene editing tool has allowed the alteration of specific gene sequences and their concomitant gene function, providing powerful technology for potato gene functional analysis and improvement of elite cultivars. This technology relies on a short RNA molecule called single guide RNA (sgRNA) that directs the Cas9 nuclease to induce a site-specific double-stranded break (DSB). Further, repair of the DSB by the error-prone non-homologous end joining (NHEJ) mechanism leads to the introduction of targeted mutations, which can be used to produce the loss of function of specific gene(s). In this chapter, we describe experimental procedures to apply the CRISPR/Cas9 technology for potato genome editing. First, we provide strategies for target selection and sgRNA design and describe a Golden Gate-based cloning system to obtain a sgRNA/Cas9-encoding binary vector. We also describe an optimized protocol for ribonucleoprotein (RNP) complex assembly. The binary vector can be used for both Agrobacterium-mediated transformation and transient expression in potato protoplasts, while the RNP complexes are intended to obtain edited potato lines through protoplast transfection and plant regeneration. Finally, we describe procedures to identify the gene-edited potato lines. The methods described here are suitable for potato gene functional analysis and breeding.
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| 8. |
- Andersson, Mariette, et al.
(författare)
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Efficient targeted multiallelic mutagenesis in tetraploid potato (Solanum tuberosum) by transient CRISPR-Cas9 expression in protoplasts
- 2017
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Ingår i: Plant Cell Reports. - : Springer Science and Business Media LLC. - 0721-7714 .- 1432-203X. ; 36, s. 117-128
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Tidskriftsartikel (refereegranskat)abstract
- Altered starch quality with full knockout of GBSS gene function in potato was achieved using CRISPR-Cas9 technology, through transient transfection and regeneration from isolated protoplasts.Site-directed mutagenesis (SDM) has shown great progress in introducing precisely targeted mutations. Engineered CRISPR-Cas9 has received increased focus compared to other SDM techniques, since the method is easily adapted to different targets. Here, we demonstrate that transient application of CRISPR-Cas9-mediated genome editing in protoplasts of tetraploid potato (Solanum tuberosum) yielded mutations in all four alleles in a single transfection, in up to 2 % of regenerated lines. Three different regions of the gene encoding granule-bound starch synthase (GBSS) were targeted under different experimental setups, resulting in mutations in at least one allele in 2-12 % of regenerated shoots, with multiple alleles mutated in up to 67 % of confirmed mutated lines. Most mutations resulted in small indels of 1-10 bp, but also vector DNA inserts of 34-236 bp were found in 10 % of analysed lines. No mutations were found in an allele diverging one bp from a used guide sequence, verifying similar results found in other plants that high homology between guide sequence and target region near the protospacer adjacent motif (PAM) site is essential. To meet the challenge of screening large numbers of lines, a PCR-based high-resolution fragment analysis method (HRFA) was used, enabling identification of multiple mutated alleles with a resolution limit of 1 bp. Full knockout of GBSS enzyme activity was confirmed in four-allele mutated lines by phenotypic studies of starch. One remaining wild-type (WT) allele was shown sufficient to maintain enough GBSS enzyme activity to produce significant amounts of amylose.
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| 9. |
- Andersson, Mariette, et al.
(författare)
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Genome editing in potato via CRISPR-Cas9 ribonucleoprotein delivery
- 2018
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Ingår i: Physiologia Plantarum. - : Wiley. - 0031-9317 .- 1399-3054. ; 164, s. 378-384
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Tidskriftsartikel (refereegranskat)abstract
- Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein-9 (CRISPR-Cas9) can be used as an efficient tool for genome editing in potato (Solanum tuberosum). From both a scientific and a regulatory perspective, it is beneficial if integration of DNA in the potato genome is avoided. We have implemented a DNA-free genome editing method, using delivery of CRISPR-Cas9 ribonucleoproteins (RNPs) to potato protoplasts, by targeting the gene encoding a granule bound starch synthase (GBSS, EC 2.4.1.242). The RNP method was directly implemented using previously developed protoplast isolation, transfection and regeneration protocols without further adjustments. Cas9 protein was preassembled with RNA produced either synthetically or by in vitro transcription. RNP with synthetically produced RNA (cr-RNP) induced mutations, i.e. indels, at a frequency of up to 9%, with all mutated lines being transgene-free. A mutagenesis frequency of 25% of all regenerated shoots was found when using RNP with in vitro transcriptionally produced RNA (IVT-RNP). However, more than 80% of the shoots with confirmed mutations had unintended inserts in the cut site, which was in the same range as when using DNA delivery. The inserts originated both from DNA template remnants from the in vitro transcription, and from chromosomal potato DNA. In 2-3% of the regenerated shoots from the RNP-experiments, mutations were induced in all four alleles resulting in a complete knockout of the GBSS enzyme function.
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| 10. |
- Andersson, Mariette, et al.
(författare)
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Inhibition of plastid PPase and NTT leads to major changes in starch and tuber formation in potato
- 2018
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Ingår i: Journal of Experimental Botany. - : Oxford University Press (OUP). - 0022-0957 .- 1460-2431. ; 69, s. 1913-1924
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Tidskriftsartikel (refereegranskat)abstract
- The importance of a plastidial soluble inorganic pyrophosphatase (psPPase) and an ATP/ ADP translocator (NTT) for starch composition and tuber formation in potato (Solanum tuberosum) was evaluated by individual and simultaneous down-regulation of the corresponding endogenous genes. Starch and amylose content of the transgenic lines were considerably lower, and granule size substantially smaller, with down-regulation of StpsPPase generating the most pronounced effects. Single-gene down-regulation of either StpsPPase or StNTT resulted in increased tuber numbers per plant and higher fresh weight yield. In contrast, when both genes were inhibited simultaneously, some lines developed only a few, small and distorted tubers. Analysis of metabolites revealed altered amounts of sugar intermediates, and a substantial increase in ADP-glucose content of the StpsPPase lines. Increased amounts of intermediates of vitamin C biosynthesis were also observed. This study suggests that hydrolysis of pyrophosphate (PPi) by action of a psPPase is vital for functional starch accumulation in potato tubers and that no additional mechanism for consuming, hydrolysing, or exporting PPi exists in the studied tissue. Additionally, it demonstrates that functional PPi hydrolysis in combination with efficient ATP import is essential for tuber formation and development.
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| 11. |
- Andersson, Mariette, et al.
(författare)
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Reduced Enzymatic Browning in Potato Tubers by Specific Editing of a Polyphenol Oxidase Gene via Ribonucleoprotein Complexes Delivery of the CRISPR/Cas9 System
- 2020
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Polyphenol Oxidases (PPOs) catalyze the conversion of phenolic substrates to quinones, leading to the formation of dark-colored precipitates in fruits and vegetables. This process, known as enzymatic browning, is the cause of undesirable changes in organoleptic properties and the loss of nutritional quality in plant-derived products. In potato (Solanum tubersoum L.), PPOs are encoded by a multi-gene family with different expression patterns. Here, we have studied the application of the CRISPR/Cas9 system to induce mutations in the StPPO2 gene in the tetraploid cultivar Desiree. We hypothesized that the specific editing of this target gene would result in a lower PPO activity in the tuber with the consequent reduction of the enzymatic browning. Ribonucleoprotein complexes (RNPs), formed by two sgRNAs and Cas9 nuclease, were transfected to potato protoplasts. Up to 68% of regenerated plants contained mutations in at least one allele of the target gene, while 24% of edited lines carried mutations in all four alleles. No off-target mutations were identified in other analyzed StPPO genes. Mutations induced in the four alleles of StPPO2 gene, led to lines with a reduction of up to 69% in tuber PPO activity and a reduction of 73% in enzymatic browning, compared to the control. Our results demonstrate that the CRISPR/Cas9 system can be applied to develop potato varieties with reduced enzymatic browning in tubers, by the specific editing of a single member of the StPPO gene family.
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| 12. |
- Andersson, Mariette, et al.
(författare)
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Tomato protoplasts as cell target for ribonucleoprotein (RNP)-mediated multiplexed genome editing
- 2021
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Ingår i: Plant Cell, Tissue and Organ Culture. - : Springer Science and Business Media LLC. - 0167-6857 .- 1573-5044. ; 144, s. 463-467
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Tidskriftsartikel (refereegranskat)abstract
- The possibility to produce plants edited in multiple genes by means of DNA-free approaches opens new perspectives for breeding purposes and acceptance of resultant genotypes. In this work, we have explored the polyethylene glycol (PEG)-mediated delivery of ribonucleoproteins (RNPs) in tomato protoplasts using a multiplexing approach (i.e. two genes targeted simultaneously using two sgRNAs per gene) for the first time. We have analysed the editing outcome in fully developed green calli and demonstrated that tomato protoplasts are a valid cell target for RNP-mediated multiplexed genome editing with high efficiency.Key message RNP could be applied with high efficiency in a multiplexing genome editing approach in tomato protoplasts.
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| 13. |
- Aslan, Selcuk, et al.
(författare)
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Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion
- 2015
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Ingår i: Transgenic Research. - : Springer Science and Business Media LLC. - 0962-8819 .- 1573-9368. ; 24, s. 945-953
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Tidskriftsartikel (refereegranskat)abstract
- Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future.
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| 14. |
- Aslan, Selcuk, et al.
(författare)
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Transient silencing of the KASII genes is feasible in Nicotiana benthamiana for metabolic engineering of wax ester composition
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- The beta-ketoacyl-ACP synthase II (KASII) is an enzyme in fatty acid biosynthesis, catalyzing the elongation of 16:0-acyl carrier protein (ACP) to 18:0-ACP in plastids. Mutations in KASII genes in higher plants can lead to lethality, which makes it difficult to utilize the gene for lipid metabolic engineering. We demonstrated previously that transient expression of plastid-directed fatty acyl reductases and wax ester synthases could result in different compositions of wax esters. We hypothesized that changing the ratio between C16 (palmitoyl-compounds) and C18 (stearoyl-compounds) in the plastidic acyl-ACP pool by inhibition of KASII expression would change the yield and composition of wax esters via substrate preference of the introduced enzymes. Here, we report that transient inhibition of KASII expression by three different RNAi constructs in leaves of N. benthamiana results in almost complete inhibition of KASII expression. The transient RNAi approach led to a shift of carbon flux from a pool of C18 fatty acids to C16, which significantly increased wax ester production in AtFAR6-containing combinations. The results demonstrate that transient inhibition of KASII in vegetative tissues of higher plants enables metabolic studies towards industrial production of lipids such as wax esters with specific quality and composition.
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| 15. |
- Aslan, Selcuk, et al.
(författare)
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Wax esters of different compositions produced via engineering of leaf chloroplast metabolism in Nicotiana benthamiana
- 2014
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Ingår i: Metabolic Engineering. - : Elsevier BV. - 1096-7176 .- 1096-7184. ; 25, s. 103-112
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Tidskriftsartikel (refereegranskat)abstract
- In a future bin based economy, renewable sources for lipid compounds at attractive cost are needed for applications where today petrochemical derivatives are dominating. Wax esters and fatty alcohols provide diverse industrial uses, such as in lubricant and surfactant production. In this study, chloroplast metabolism was engineered to divert intermediates from de nova fatty acid biosynthesis to wax ester synthesis. To accomplish this, chloroplast targeted fatty acyl recluctases (EAR) and wax ester synthases (WS) were transiently expressed in Nic"onana benthamiuna loaves. Wax esters of different qualities and quantities were produced providing insights to the properties and interaction of the individual enzymes used. In particular, a phytyl ester synthase was found to be a premium candidate for medium chain wax ester synthesis. Catalytic activities of FAR and WS were also expressed as a fusion protein and determined functionally equivalent to the expression of individual enzymes for wax ester synthesis in chloroplasts. (C) 2014 The Authors. Published by Elsevier Inc. On behalf of International Metabolic Engineering Society.
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| 16. |
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| 17. |
- Carlsson, Anders, et al.
(författare)
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Replacing fossil oil with fresh oil - with what and for what?
- 2011
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Ingår i: European Journal of Lipid Science and Technology. - : Wiley. - 1438-7697 .- 1438-9312. ; 113, s. 812-831
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Forskningsöversikt (refereegranskat)abstract
- Industrial chemicals and materials are currently derived mainly from fossil-based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil-based raw materials, provided that their composition can be matched to end-use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably > 90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end-use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas.Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non-renewable and polluting fossil-based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon-neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.
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| 18. |
- Demski, Kamil, et al.
(författare)
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Manufacturing specialized wax esters in plants
- 2022
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Ingår i: Metabolic Engineering. - : Elsevier BV. - 1096-7176 .- 1096-7184. ; 72, s. 391-402
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Tidskriftsartikel (refereegranskat)abstract
- Biologically produced wax esters can fulfil different industrial purposes. These functionalities almost drove the sperm whale to extinction from hunting. After the ban on hunting, there is a niche in the global market for biolubricants with properties similar to spermaceti. Wax esters can also serve as a mechanism for producing insect sex pheromone fatty alcohols. Pheromone-based mating disruption strategies are in high demand to replace the toxic pesticides in agriculture and manage insect plagues threatening our food and fiber reserves. In this study we set out to investigate the possibilities of in planta assembly of wax esters, for specific applications, through transient expression of various mix-and-match combinations of genes in Nicotiana benthamiana leaves. Our synthetic biology designs were outlined in order to pivot plant lipid metabolism into producing wax esters with targeted fatty acyl and fatty alcohols moieties. Through this approach we managed to obtain industrially important spermaceti-like wax esters enriched in medium-chain fatty acyl and/or fatty alcohol moieties of wax esters. Via employment of plant codon-optimized moth acyl-CoA desaturases we also managed to capture unusual, unsaturated fatty alcohol and fatty acyl moieties, structurally similar to moth pheromone compounds, in plant-accumulated wax esters. Comparison between outcomes of different experimental designs identified targets for stable transformation to accumulate specialized wax esters and helped us to recognize possible bottlenecks of such accumulation.
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| 19. |
- Ding, Bao-Jian, et al.
(författare)
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A plant factory for moth pheromone production
- 2014
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 5, s. 1-3353
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Tidskriftsartikel (refereegranskat)abstract
- Moths depend on pheromone communication for mate finding and synthetic pheromones are used for monitoring or disruption of pheromone communication in pest insects. Here we produce moth sex pheromone, using Nicotiana benthamiana as a plant factory, by transient expression of up to four genes coding for consecutive biosynthetic steps. We specifically produce multicomponent sex pheromones for two species. The fatty alcohol fractions from the genetically modified plants are acetylated to mimic the respective sex pheromones of the small ermine moths Yponomeuta evonymella and Y. padella. These mixtures are very efficient and specific for trapping of male moths, matching the activity of conventionally produced pheromones. Our long-term vision is to design tailor-made production of any moth pheromone component in genetically modified plants. Such semisynthetic preparation of sex pheromones is a novel and cost-effective way of producing moderate to large quantities of pheromones with high purity and a minimum of hazardous waste.
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| 20. |
- Djamnezhad, Dariush, et al.
(författare)
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Good behavior game - study protocol for a randomized controlled trial of a preventive behavior management program in a Swedish school context
- 2023
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Ingår i: Frontiers in Psychiatry. - 1664-0640. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early conduct problems and school failure are prominent risk factors for several adverse outcomes in later life. With the potential of reaching many children at early stages of their life, school-based interventions constitute a valuable approach to universal prevention. Good behavior game (GBG) is a promising school-based behavior management program, having shown immediate reductions in conduct problems along with several long-term positive effects. Adapting interventions to new contexts may however affect their effectiveness. The current study aims to evaluate the effectiveness of a Swedish adaption of GBG under pragmatic conditions. The intervention is hypothesized to reduce conduct problems in the classroom (primary outcome). Secondary analyses will investigate changes in conduct problems in common school areas, classroom climate, teacher collective efficacy, on-task behavior, as well as investigating behavioral management practices, implementation, and barriers to implementation. Methods: This is a cluster-randomized trial with two parallel groups. Schools will be randomized (1,1, stratified by their areas sociodemographic index score) to be provided training in GBG or perform business-as-usual. The intervention and data collection lasts for a school year. Data will be collected at three time points: at baseline in the beginning of the school year (prior to training in GBG), after three months, and after nine months (at the end of the school year; primary endpoint). Data consists of teacher-rated measures of conduct problems, classroom climate, teacher collective efficacy, behavior management practices, and implementation factors, along with demographic factors. In addition, data will be collected by independent and blinded observers using corresponding measures in a subset of randomly chosen classrooms. Procedural fidelity will be rated and collected by GBG-trainers during nine observations throughout the school year. Statistical analysis will include frequentist intention-to-treat analysis, and comparisons of estimates with a corresponding Bayesian model using weakly informative priors. The study has currently completed data collection. Discussion: This study will provide knowledge in universal prevention and school-based interventions with high reach, as well as specific knowledge concerning the effectiveness of an adapted version of GBG under real-world conditions, along with factors affecting its implementation and effects.
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| 21. |
- Doan, Thuy, et al.
(författare)
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Biochemical characteristics of AtFAR2, a fatty acid reductase from Arabidopsis thaliana that reduces fatty acyl-CoA and -ACP substrates into fatty alcohols
- 2016
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Ingår i: Acta Biochimica Polonica. - : Polskie Towarzystwo Biochemiczne (Polish Biochemical Society). - 0001-527X .- 1734-154X. ; 63, s. 565-570
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Tidskriftsartikel (refereegranskat)abstract
- Fatty alcohols and derivatives are important for proper deposition of a functional pollen wall. Mutations in specific genes encoding fatty acid reductases (FAR) responsible for fatty alcohol production cause abnormal development of pollen. A disrupted AtFAR2 (MS2) gene in Arabidopsis thaliana results in pollen developing an abnormal exine layer and a reduced fertility phenotype. AtFAR2 has been shown to be targeted to chloroplasts and in a purified form to be specific for acyl-ACP substrates. Here, we present data on the in vitro and in planta characterizations of AtFAR2 from A. thaliana and show that this enzyme has the ability to use both, C16:0-ACPand C16:0-CoA, as substrates to produce C16:0-alcohol. Our results further show that AtFAR2 is highly similar in properties and substrate specificity to AtFAR6 for which in vitro data has been published, and which is also a chloroplast localized enzyme. This suggests that although AtFAR2 is the major enzyme responsible for exine layer functionality, AtFAR6 might provide functional redundancy to AtFAR2.
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| 22. |
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| 23. |
- Eriksson, Dennis, et al.
(författare)
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A Welcome Proposal to Amend the GMO Legislation of the EU
- 2018
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Ingår i: Trends in Biotechnology. - : Elsevier BV. - 0167-7799 .- 1879-3096. ; 36, s. 1100-1103
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Annan publikation (refereegranskat)abstract
- Is the European Union (EU) regulatory framework for genetically modified organisms (GMOs) adequate for emerging techniques, such as genome editing? This has been discussed extensively for more than 10 years. A recent proposal from The Netherlands offers a way to break the deadlock. Here, we discuss how the proposal would affect examples from public plant research.
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| 24. |
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| 25. |
- Fält, Ann-Sofie, et al.
(författare)
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Protoplast-Based Method for Genome Editing in Tetraploid Potato
- 2021
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Ingår i: Crop Breeding : Genetic Improvement Methods. - New York, NY : Springer US. - 9781071612002 ; :2264, s. 177-186
-
Bokkapitel (refereegranskat)abstract
- The cultivated potato is tetraploid with four probably equivalent loci for each gene. A potato variety is furthermore commonly genetically heterogeneous and selected based on a beneficial genetic context which is maintained by clonal propagation. When introducing genetic changes by genome editing it is then desirable to achieve edits in all four loci for a certain gene target. This is in order to avoid crosses to achieve homozygosity for edited gene loci and at the same time reduce risk of inbreeding depression. In such a context transient transfection of protoplasts for the introduction of mutations, avoiding stable insertion of foreign DNA, would be very attractive. The protocol of this chapter has been shown to be applicable for the introduction of mutations by DNA vectors containing expression cassettes of TALEN, Cas9, and Cas9 deaminase fusions together with sgRNA expression cassettes on either single or separate vectors. Furthermore, the protoplast-based system has been shown to work very efficiently for mutations introduced by in vitro-produced and transfected RNP (ribonucleoprotein) complexes.
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| 26. |
- Grimberg, Åsa, et al.
(författare)
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Transcriptional transitions in Nicotiana benthamiana leaves upon induction of oil synthesis by WRINKLED1 homologs from diverse species and tissues
- 2015
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Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 15, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Background: Carbon accumulation and remobilization are essential mechanisms in plants to ensure energy transfer between plant tissues with different functions or metabolic needs and to support new generations. Knowledge about the regulation of carbon allocation into oil (triacylglycerol) in plant storage tissue can be of great economic and environmental importance for developing new high-yielding oil crops. Here, the effect on global gene expression as well as on physiological changes in leaves transiently expressing five homologs of the transcription factor WRINKLED1 (WRI1) originating from diverse species and tissues; Arabidopsis thaliana and potato (Solanum tuberosum) seed embryo, poplar (Populus trichocarpa) stem cambium, oat (Avena sativa) grain endosperm, and nutsedge (Cyperus esculentus) tuber parenchyma, were studied by agroinfiltration in Nicotiana benthamiana.Results: All WRI1 homologs induced oil accumulation when expressed in leaf tissue. Transcriptome sequencing revealed that all homologs induced the same general patterns with a drastic shift in gene expression profiles of leaves from that of a typical source tissue to a source-limited sink-like tissue: Transcripts encoding enzymes for plastid uptake and metabolism of phosphoenolpyruvate, fatty acid and oil biosynthesis were up-regulated, as were also transcripts encoding starch degradation. Transcripts encoding enzymes in photosynthesis and starch synthesis were instead down-regulated. Moreover, transcripts representing fatty acid degradation were up-regulated indicating that fatty acids might be degraded to feed the increased need to channel carbons into fatty acid synthesis creating a futile cycle. RT-qPCR analysis of leaves expressing Arabidopsis WRI1 showed the temporal trends of transcripts selected as 'markers' for key metabolic pathways one to five days after agroinfiltration. Chlorophyll fluorescence measurements of leaves expressing Arabidopsis WRI1 showed a significant decrease in photosynthesis, even though effect on starch content could not be observed.Conclusions: This data gives for the first time a general view on the transcriptional transitions in leaf tissue upon induction of oil synthesis by WRI1. This yields important information about what effects WRI1 may exert on global gene expression during seed and embryo development. The results suggest why high oil content in leaf tissue cannot be achieved by solely transcriptional activation by WRI1, which can be essential knowledge in the development of new high-yielding oil crops.
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| 27. |
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| 28. |
- Guan, Rui, et al.
(författare)
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RNAi Targeting Putative Genes in Phosphatidylcholine Turnover Results in Significant Change in Fatty Acid Composition in Crambe abyssinica Seed Oil
- 2015
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Ingår i: Lipids. - : Wiley. - 0024-4201 .- 1558-9307. ; 50, s. 407-416
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the importance of three enzymes, LPCAT, PDCT and PDAT, involved in acyl turnover in phosphatidylcholine in order to explore the possibility of further increasing erucic acid (22:1) content in Crambe seed oil. The complete coding sequences of LPCAT1-1 and LPCAT1-2 encoding lysophosphatidylcholine acyltransferase (LPCAT), PDCT1 and PDCT2 encoding phosphatidylcholine:diacylglycerol cholinephosphotransferase (PDCT), and PDAT encoding phospholipid:diacylglycerol acyltransferase (PDAT) were cloned from developing Crambe seeds. The alignment of deduced amino acid sequences displayed a high similarity to the Arabidopsis homologs. Transgenic lines expressing RNA interference (RNAi) targeting either single or double genes showed significant changes in the fatty acid composition of seed oil. An increase in oleic acid (18:1) was observed, to varying degrees, in all of the transgenic lines, and a cumulative effect of increased 18:1 was shown in the LPCAT-PDCT double-gene RNAi. However, LPCAT single-gene RNAi led to a decrease in 22:1 accumulation, while PDCT or PDAT single-gene RNAi had no obvious effect on the level of 22:1. In agreement with the abovementioned oil phenotypes, the transcript levels of the target genes in these transgenic lines were generally reduced compared to wild-type levels. In this paper, we discuss the potential to further increase the 22:1 content in Crambe seed oil through downregulation of these genes in combination with fatty acid elongase and desaturases.
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| 29. |
- Hofvander, Per, et al.
(författare)
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A prokaryotic acyl-CoA reductase performing reduction of fatty acyl-CoA to fatty alcohol
- 2011
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 585, s. 3538-3543
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Annan publikation (refereegranskat)abstract
- The reduction of acyl-CoA or acyl-ACP to fatty alcohol occurs via a fatty aldehyde intermediate. In prokaryotes this reaction is thought to be performed by separate enzymes for each reduction step while in eukaryotes these reactions are performed by a single enzyme without the release of the intermediate fatty aldehyde. However, here we report that a purified fatty acyl reductase from Marinobacter aquaeolei VT8, evolutionarily related to the fatty acyl reductases in eukaryotes, catalysed both reduction steps. Thus, there are at least two pathways existing among prokaryotes for the reduction of activated acyl substrates to fatty alcohol. The Marinobacter fatty acyl reductase studied has a wide substrate range in comparison to what can be found among enzymes so far studied in eukaryotes. (C) 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
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| 30. |
- Hofvander, Per, et al.
(författare)
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Potato trait development going fast-forward with genome editing
- 2022
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Ingår i: Trends in Genetics. - : Elsevier BV. - 0168-9525. ; 38, s. 218-221
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Tidskriftsartikel (refereegranskat)abstract
- Implementations and improvements of genome editing techniques used in plant science have increased exponentially. For some crops, such as potato, the use of transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR) has moved to the next step of trait development and field trials, and should soon be applied to commercial cultivation.
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| 31. |
- Hofvander, Per, et al.
(författare)
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Potato tuber expression of Arabidopsis WRINKLED1 increase triacylglycerol and membrane lipids while affecting central carbohydrate metabolism
- 2016
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Ingår i: Plant Biotechnology Journal. - : Wiley. - 1467-7644 .- 1467-7652. ; 14, s. 1883-1898
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Tidskriftsartikel (refereegranskat)abstract
- Tuber and root crops virtually exclusively accumulate storage products in the form of carbohydrates. An exception is yellow nutsedge (Cyperus esculentus) in which tubers have the capacity to store starch and triacylglycerols (TAG) in roughly equal amounts. This suggests that a tuber crop can efficiently handle accumulation of energy dense oil. From a nutritional as well as economic aspect, it would be of interest to utilize the high yield capacity of tuber or root crops for oil accumulation similar to yellow nutsedge. The transcription factor WRINKLED1 from Arabidopsis thaliana, which in seed embryos induce fatty acid synthesis, has been shown to be a major factor for oil accumulation. WRINKLED1 was expressed in potato (Solanum tuberosum) tubers to explore whether this factor could impact tuber metabolism. This study shows that a WRINKLED1 transcription factor could induce triacylglycerol accumulation in tubers of transformed potato plants grown in field (up to 12 nmol TAG/mg dry weight, 1% of dry weight) together with a large increase in polar membrane lipids. The changes in metabolism further affected starch accumulation and composition concomitant with massive increases in sugar content.
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| 32. |
- Hofvander, Per, et al.
(författare)
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Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry
- 2013
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Ingår i: Plant Methods. - : Springer Science and Business Media LLC. - 1746-4811. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Conclusions: We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples like cuticular lipid extracts to gain an overview on the molecular species composition. We confirm previous results from APCI-MS and GC-MS analysis, which showed that fragmentation patterns are highly dependent on the double bond distribution between the fatty alcohol and the fatty acid part of the wax ester.
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| 33. |
- Jayarathna, Shishanthi, et al.
(författare)
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GBSS mutations in an SBE mutated background restore the potato starch granule morphology and produce ordered granules despite differences to native molecular structure
- 2024
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 331
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Tidskriftsartikel (refereegranskat)abstract
- Potato starch with mutations in starch branching enzyme genes (SBEI, SBEII) and granule-bound starch synthase gene (GBSS) was characterized for molecular and thermal properties. Mutations in GBSS were here stacked to a previously developed SBEI and SBEII mutation line. Additionally, mutations in the GBSS gene alone were induced in the wild-type variety for comparison. The parental line with mutations in the SBE genes showed a ∼ 40 % increase in amylose content compared with the wild-type. Mutations in GBSS-SBEI-SBEII produced non-waxy, low-amylose lines compared with the wild-type. An exception was a line with one remaining GBSS wild-type allele, which displayed ∼80 % higher amylose content than wild-type. Stacked mutations in GBSS in the SBEI-SBEII parental line caused alterations in amylopectin chain length distribution and building block size categories of whole starch. Correlations between size categories of building blocks and unit chains of amylopectin were observed. Starch in GBSS-SBEI-SBEII mutational lines had elevated peak temperature of gelatinization, which was positively correlated with large building blocks.
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| 34. |
- Jin, Yunkai, et al.
(författare)
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Improved bioenergy value of residual rice straw by increased lipid levels from upregulation of fatty acid biosynthesis
- 2023
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Ingår i: Biotechnology for Biofuels and Bioproducts. - 2731-3654. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundRice (Oryza sativa) straw is a common waste product that represents a considerable amount of bound energy. This energy can be used for biogas production, but the rate and level of methane produced from rice straw is still low. To investigate the potential for an increased biogas production from rice straw, we have here utilized WRINKLED1 (WRI1), a plant AP2/ERF transcription factor, to increase triacylglycerol (TAG) biosynthesis in rice plants. Two forms of Arabidopsis thaliana WRI1 were evaluated by transient expression and stable transformation of rice plants, and transgenic plants were analyzed both for TAG levels and biogas production from straw.ResultsBoth full-length AtWRI1, and a truncated form lacking the initial 141 amino acids (including the N-terminal AP2 domain), increased fatty acid and TAG levels in vegetative and reproductive tissues of Indica rice. The stimulatory effect of the truncated AtWRI1 was significantly lower than that of the full-length protein, suggesting a role for the deleted AP2 domain in WRI1 activity. Full-length AtWRI1 increased TAG levels also in Japonica rice, indicating a conserved effect of WRI1 in rice lipid biosynthesis. The bio-methane production from rice straw was 20% higher in transformants than in the wild type. Moreover, a higher producing rate and final yield of methane was obtained for rice straw compared with rice husks, suggesting positive links between methane production and a high amount of fatty acids.ConclusionsOur results suggest that heterologous WRI1 expression in transgenic plants can be used to improve the metabolic potential for bioenergy purposes, in particular methane production.
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| 35. |
- Kushwaha, Sandeep Kumar, et al.
(författare)
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Charting oat (Avena sativa) embryo and endosperm transcription factor expression reveals differential expression of potential importance for seed development
- 2019
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Ingår i: Molecular Genetics and Genomics. - : Springer Science and Business Media LLC. - 1617-4615 .- 1617-4623. ; 294, s. 1183-1197
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Tidskriftsartikel (refereegranskat)abstract
- Uniquely, oat, among cereals, accumulates an appreciable amount of oil in the endosperm together with starch. Oat is also recognized for its soluble fibers in the form of beta-glucans. Despite high and increasing interest in oat yield and quality, the genetic and molecular understanding of oat grain development is still very limited. Transcription factors (TFs) are important regulatory components for plant development, product quality and yield. This study aimed to develop a workflow to determine seed tissue specificity of transcripts encoding transcription factors to reveal differential expression of potential importance for storage compound deposition and quality characters in oat. We created a workflow through the de novo assembly of sequenced seed endosperm and embryo, and publicly available oat seed RNAseq dataset, later followed by TF identification. RNAseq data were assembled into 33,878 transcripts with approximately 90% completeness. A total of 3875 putative TF encoding transcripts were identified from the oat hybrid assemblies. Members of the B3, bHLH, bZIP, C3H, ERF, NAC, MYB and WRKY families were the most abundant TF transcripts. A total of 514 transcripts which were differentially expressed between embryo and endosperm were identified with a threshold of 16-fold expression difference. Among those, 36 TF transcript homologs, belonging to 7 TF families, could be identified through similarity search in wheat embryo and endosperm EST libraries of NCBI Unigene database, and almost all the closest homologs were specifically expressed in seed when explored in WheatExp database. We verified our findings by cloning, sequencing and finally confirming differential expression of two TF encoding transcripts in oat seed embryo and endosperm. The developed workflow for identifying tissue-specific transcription factors allows further functional characterization of specific genes to increase our understanding of grain filling and quality.
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| 36. |
- Liu, Ying, et al.
(författare)
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Establishment of a DNA-free genome editing and protoplast regeneration method in cultivated tomato (Solanum lycopersicum)
- 2022
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Ingår i: Plant Cell Reports. - : Springer Science and Business Media LLC. - 0721-7714 .- 1432-203X.
-
Tidskriftsartikel (refereegranskat)abstract
- Key message We have established a DNA-free genome editing method via ribonucleoprotein-based CRISPR/Cas9 in cultivated tomato and obtained mutant plants regenerated from transfected protoplasts with a high mutation rate. The application of genome editing as a research and breeding method has provided many possibilities to improve traits in many crops in recent years. In cultivated tomato (Solanum lycopersicum), so far only stable Agrobacterium-mediated transformation carrying CRISPR/Cas9 reagents has been established. Shoot regeneration from transfected protoplasts is the major bottleneck in the application of DNA-free genome editing via ribonucleoprotein-based CRISPR/Cas9 method in cultivated tomato. In this study, we report the implementation of a transgene-free breeding method for cultivated tomato by CRISPR/Cas9 technology, including the optimization of protoplast isolation and overcoming the obstacle in shoot regeneration from transfected protoplasts. We have identified that the shoot regeneration medium containing 0.1 mg/L IAA and 0.75 mg/L zeatin was the best hormone combination with a regeneration rate of up to 21.3%. We have successfully obtained regenerated plants with a high mutation rate four months after protoplast isolation and transfection. Out of 110 regenerated M-0 plants obtained, 35 (31.8%) were mutated targeting both SP and SP5G genes simultaneously and the editing efficiency was up to 60% in at least one allele in either SP or SP5G genes.
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| 37. |
- Löfstedt, Christer, et al.
(författare)
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METHODS OF PRODUCING INSECT PHEROMONES
- 2021
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Patent (övrigt vetenskapligt/konstnärligt)abstract
- The present disclosure relates to methods of producing insect pheromone precursors and genetically modified plants capable of producing insect pheromone precursors. The genetically modified plants include a heterologous gene encoding at least one silencing suppressor protein and at least one enzyme selected from the group consisting of a fatty acyl desaturase, a fatty acyl elongase, a fatty acyl reductase, and an acyl-CoA oxidase.
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| 38. |
- Ng'uni, Dickson, et al.
(författare)
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Comparative genetic diversity and nutritional quality variation among some important Southern African sorghum accessions (Sorghum bicolor (L.) Moench)
- 2012
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Ingår i: Australian Journal Of Crop Science. - 1835-2693 .- 1835-2707. ; 6, s. 54-64
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Tidskriftsartikel (refereegranskat)abstract
- Determination of genetic diversity and nutritional value is useful for varietal improvement. Fourteen sorghum accessions, six from Malawi (MW), four each from Tanzania (TZ) and Zambia (ZMB) considered most common and widely grown varieties in those countries were assessed for genetic diversity based on ten SSR loci and grain-Fe, Zn, total protein and starch contents. Sorghum accessions exhibited significant variation for protein, total starch content and grain-Zn (p<0.001) and grain-Fe (p<0.05). Grain-Fe content ranged from 2.8 to 6.3 mg/100g and grain-Zn content ranged 2.3 - 5.5 mg/100g. Grain protein content ranged from 9.7 to 16.3%. TZ4031 from Tanzania was superior in grain-Zn content while MW734 from Malawi was high in grain-Fe and protein contents. Zambian accessions were significantly higher in total starch content. Similarly, Tanzanian accessions were significantly superior in grain-Zn content. Protein content was significantly positive correlated with grain-Zn (r = 0.42). Significant and highly positive correlation (r = 0.49) was revealed between grain-Fe and Zn content. Nei’s gene diversity revealed higher genetic variation within Malawian accessions than in other accessions used in the study. The lowest within accessions genetic diversity was exhibited by Tanzanian accessions. Cluster and principal coordinate analyses revealed similarity between Malawian and Tanzanian accessions. The results suggest presence of genetic diversity for grain-Fe, Zn, protein and starch contents for food purposes and as resource for varietal improvement. MW734, TZ4031 and TZ3966 were identified as a potential resource material for grain-Fe and Zn variety enrichment programme. However, further research is recommended for evaluation of the compositional stability of potential sorghum accessions across various environmental conditions
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| 39. |
- Ohm, Hannah, et al.
(författare)
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Spatio-temporal transcriptome and storage compound profiles of developing faba bean (Vicia faba) seed tissues
- 2024
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Ingår i: Frontiers in Plant Science. - 1664-462X. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Faba bean (Vicia faba) is a legume grown in diverse climate zones with a high potential for increased cultivation and use in food due to its nutritional seeds. In this study, we characterized seed tissue development in faba bean to identify key developmental processes; from embryo expansion at the expense of the endosperm to the maturing storage stages of the bean seed. A spatio-temporal transcriptome profiling analysis, combined with chemical nutrient analysis of protein, starch, and lipid, of endosperm and embryo tissues at different developmental stages, revealed gene expression patterns, transcriptional networks, and biochemical pathways in faba bean. We identified key players in the LAFL (LEC1, ABI3, FUS3, and LEC2) transcription factor network as well as their major repressors VAL1 and ASIL1. Our results showed that proteins accumulated not only in the embryo but also in the endosperm. Starch accumulated throughout seed development and oil content increased during seed development but at very low levels. The patterns of differentially expressed transcripts encoding proteins with functions in the corresponding metabolic pathways for the synthesis of these storage compounds, to a high extent, aligned with these findings. However, the early expression of transcripts encoding WRI1 combined with the late expression of oil body proteins indicated a not manifested high potential for lipid biosynthesis and oil storage. Altogether, this study contributes to increased knowledge regarding seed developmental processes applicable to future breeding methods and seed quality improvement for faba bean.
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| 40. |
- Ortiz Rios, Rodomiro Octavio, et al.
(författare)
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Oil crops for the future
- 2020
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Ingår i: Current Opinion in Plant Biology. - : Elsevier BV. - 1369-5266 .- 1879-0356. ; 56, s. 181-189
-
Forskningsöversikt (refereegranskat)abstract
- Agriculture faces enormous challenges including the need to substantially increase productivity, reduce environmental footprint, and deliver renewable alternatives that are being addressed by developing new oil crops for the future. The efforts include domestication of Lepidium spp. using genomics-aided breeding as a cold hardy perennial high-yielding oil crop that provides substantial environmental benefits, expands the geography for oil crops, and improves farmers’ economy. In addition, genetic engineering in Crambe abyssinica may lead to a dedicated industrial oil crop to replace fossil oil. Redirection of photosynthates from starch to oil in plant tubers and cereal endosperm also provides a path for enhancing oil production to meet the growing demands for food, fuel, and biomaterials. Insect pheromone components are produced in seed oil plants in a cost-effective and environmentally friendly pest management replacing synthetically produced pheromones. Autophagy is explored for increasing crop fitness and oil accumulation using genetic engineering in Arabidopsis.
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| 41. |
- Schepke, Elizabeth, et al.
(författare)
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Supratentorial CNS-PNETs in children; a Swedish population-based study with molecular re-evaluation and long-term follow-up
- 2023
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Ingår i: Clinical Epigenetics. - : Springer Science and Business Media LLC. - 1868-7075 .- 1868-7083. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundMolecular analyses have shown that tumours diagnosed as supratentorial primitive neuro-ectodermal tumours of the central nervous system (CNS-PNETs) in the past represent a heterogenous group of rare childhood tumours including high-grade gliomas (HGG), ependymomas, atypical teratoid/rhabdoid tumours (AT/RT), CNS neuroblastoma with forkhead box R2 (FOXR2) activation and embryonal tumour with multi-layered rosettes (ETMR). All these tumour types are rare and long-term clinical follow-up data are sparse. We retrospectively re-evaluated all children (0-18 years old) diagnosed with a CNS-PNET in Sweden during 1984-2015 and collected clinical data.MethodsIn total, 88 supratentorial CNS-PNETs were identified in the Swedish Childhood Cancer Registry and from these formalin-fixed paraffin-embedded tumour material was available for 71 patients. These tumours were histopathologically re-evaluated and, in addition, analysed using genome-wide DNA methylation profiling and classified by the MNP brain tumour classifier.ResultsThe most frequent tumour types, after histopathological re-evaluation, were HGG (35%) followed by AT/RT (11%), CNS NB-FOXR2 (10%) and ETMR (8%). DNA methylation profiling could further divide the tumours into specific subtypes and with a high accuracy classify these rare embryonal tumours. The 5 and 10-year overall survival (OS) for the whole CNS-PNET cohort was 45% +/- 12% and 42% +/- 12%, respectively. However, the different groups of tumour types identified after re-evaluation displayed very variable survival patterns, with a poor outcome for HGG and ETMR patients with 5-year OS 20% +/- 16% and 33% +/- 35%, respectively. On the contrary, high PFS and OS was observed for patients with CNS NB-FOXR2 (5-year 100% for both). Survival rates remained stable even after 15-years of follow-up.ConclusionsOur findings demonstrate, in a national based setting, the molecular heterogeneity of these tumours and show that DNA methylation profiling of these tumours provides an indispensable tool in distinguishing these rare tumours. Long-term follow-up data confirms previous findings with a favourable outcome for CNS NB-FOXR2 tumours and poor chances of survival for ETMR and HGG.
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| 42. |
- Sharma, Shrikant, et al.
(författare)
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A seed-like proteome in oil-rich tubers
- 2022
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Ingår i: Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 112, s. 518-534
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Tidskriftsartikel (refereegranskat)abstract
- There are numerous examples of plant organs or developmental stages that are desiccation-tolerant and can withstand extended periods of severe water loss. One prime example are seeds and pollen of many spermatophytes. However, in some plants, also vegetative organs can be desiccation-tolerant. One example are the tubers of yellow nutsedge (Cyperus esculentus), which also store large amounts of lipids similar to seeds. Interestingly, the closest known relative, purple nutsedge (Cyperus rotundus), generates tubers that do not accumulate oil and are not desiccation-tolerant. We generated nanoLC-MS/MS-based proteomes of yellow nutsedge in five replicates of four stages of tuber development and compared them to the proteomes of roots and leaves, yielding 2257 distinct protein groups. Our data reveal a striking upregulation of hallmark proteins of seeds in the tubers. A deeper comparison to the tuber proteome of the close relative purple nutsedge (C. rotundus) and a previously published proteome of Arabidopsis seeds and seedlings indicates that indeed a seed-like proteome was found in yellow but not purple nutsedge. This was further supported by an analysis of the proteome of a lipid droplet-enriched fraction of yellow nutsedge, which also displayed seed-like characteristics. One reason for the differences between the two nutsedge species might be the expression of certain transcription factors homologous to ABSCISIC ACID INSENSITIVE3, WRINKLED1, and LEAFY COTYLEDON1 that drive gene expression in Arabidopsis seed embryos.
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| 43. |
- Sharma, Shrikant, et al.
(författare)
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Pho1a (plastid starch phosphorylase) is duplicated and essential for normal starch granule phenotype in tubers of Solanum tuberosum L
- 2023
-
Ingår i: Frontiers in Plant Science. - 1664-462X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Reserve starch from seeds and tubers is a crucial plant product for human survival. Much research has been devoted to quantitative and qualitative aspects of starch synthesis and its relation to abiotic factors of importance in agriculture. Certain aspects of genetic factors and enzymes influencing carbon assimilation into starch granules remain elusive after many decades of research. Starch phosphorylase (Pho) can operate, depending on metabolic conditions, in a synthetic and degradative pathway. The plastidial form of the enzyme is one of the most highly expressed genes in potato tubers, and the encoded product is imported into starch-synthesizing amyloplasts. We identified that the genomic locus of a Pho1a-type starch phosphorylase is duplicated in potato. Our study further shows that the enzyme is of importance for a normal starch granule phenotype in tubers. Null mutants created by genome editing display rounded starch granules in an increased number that contained a reduced ratio of apparent amylose in the starch.
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| 44. |
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| 45. |
- Turesson, Helle, et al.
(författare)
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Characterization of oil and starch accumulation in tubers of Cyperus esculentus var. sativus (Cyperaceae): A novel model system to study oil reserves in nonseed tissues
- 2010
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 97:11, s. 1884-1893
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Tidskriftsartikel (refereegranskat)abstract
- Premise of the study: Storage oil (triacylglycerol) accumulates in tissues such as the embryo and endosperm of seeds and the fruit mesocarp, but seldom in underground organs. As a rare exception, cultivated variants of yellow nutsedge (Cyperus esculentus) contain high amounts of both oil and starch in the mature tubers. Methods: Biochemical analyses and light and electron microscopy were used to study the accumulation patterns of storage nutrients in developing nutsedge tubers. Key results: During the initial phase of tuber development, the conducting rhizome tissue is transformed into a storage compartment, then massive storage reserves accumulate in the tuber. At the beginning of tuber development, a large sugar load coincided with the onset of starch accumulation. Oil accumulation started later, concomitant with a substantial drop in the sugar content. Initially, oil accumulated at a lower rate compared to starch, but the rate later increased; after 6 wk, oil made up 24% of tuber dry mass, while starch made up 32%. Protein concentration changed only a small amount throughout this development. Oil and starch accumulated in the same cells throughout the tubers in a sequential fashion during tuber development. Conclusions: The developmental pattern in the build up of storage nutrients in the tubers highlights nutsedge as a novel model plant, having potential to significantly widen our understanding on how synthesis of storage reserves, and in particular oils, is regulated and directed in nonseed tissues such as tubers and roots.
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| 46. |
- Turesson, Helle, et al.
(författare)
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Starch biosynthetic genes and enzymes are expressed and active in the absence of starch accumulation in sugar beet tap-root
- 2014
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Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: Starch is the predominant storage compound in underground plant tissues like roots and tubers. An exception is sugar beet tap-root (Beta vulgaris ssp altissima) which exclusively stores sucrose. The underlying mechanism behind this divergent storage accumulation in sugar beet is currently not fully known. From the general presence of starch in roots and tubers it could be speculated that the lack in sugar beet tap-roots would originate from deficiency in pathways leading to starch. Therefore with emphasis on starch accumulation, we studied tap-roots of sugar beet using parsnip (Pastinaca sativa) as a comparator. Results: Metabolic and structural analyses of sugar beet tap-root confirmed sucrose as the exclusive storage component. No starch granules could be detected in tap-roots of sugar beet or the wild ancestor sea beet (Beta vulgaris ssp. maritima). Analyses of parsnip showed that the main storage component was starch but tap-root tissue was also found to contain significant levels of sugars. Surprisingly, activities of four main starch biosynthetic enzymes, phosphoglucomutase, ADP-glucose pyrophosphorylase, starch synthase and starch branching enzyme, were similar in sugar beet and parsnip tap-roots. Transcriptional analysis confirmed expression of corresponding genes. Additionally, expression of genes involved in starch accumulation such as for plastidial hexose transportation and starch tuning functions could be determined in tap-roots of both plant species. Conclusion: Considering underground storage organs, sugar beet tap-root upholds a unique property in exclusively storing sucrose. Lack of starch also in the ancestor sea beet indicates an evolved trait of biological importance. Our findings in this study show that gene expression and enzymatic activity of main starch biosynthetic functions are present in sugar beet tap-root during storage accumulation. In view of this, the complete lack of starch in sugar beet tap-roots is enigmatic.
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| 47. |
- Wang, Hong Lei, et al.
(författare)
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Insect pest management with sex pheromone precursors from engineered oilseed plants
- 2022
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Ingår i: Nature Sustainability. - : Springer Science and Business Media LLC. - 2398-9629.
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Tidskriftsartikel (refereegranskat)abstract
- Pheromones have become an environmentally friendly alternative to conventional insecticides for pest control. Most current pheromone-based pest control products target lepidopteran pests of high-value crops, as today’s manufacturing processes cannot yet produce pheromones at low enough costs to enable their use for lower-value crops, especially commodity crops. Camelina sativa seeds genetically modified to express (Z)-11-hexadecenoic acid, a sex pheromone precursor of several moth species, provided the oil from which the precursor was isolated, purified and transformed into the final pheromone. Trap lures containing this pheromone were then assessed for their capacity to manage moth pests in the field. Plant-derived pheromone lures proved equally effective as synthetic pheromone lures in monitoring the diamondback moth, Plutella xylostella, in cabbage and disrupting mating of cotton bollworm, Helicoverpa armigera, in common bean fields. Our study demonstrates the biological efficacy and economic feasibility of pheromone production in plant factories by metabolic engineering of an oilseed crop.
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| 48. |
- Xia, Yihan, 1990, et al.
(författare)
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Green Chemistry Production of Codlemone, the Sex Pheromone of the Codling Moth (Cydia pomonella), by Metabolic Engineering of the Oilseed Crop Camelina (Camelina sativa)
- 2021
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 1573-1561 .- 0098-0331. ; 47:12, s. 950-967
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Tidskriftsartikel (refereegranskat)abstract
- Synthetic pheromones have been used for pest control over several decades. The conventional synthesis of di-unsaturated pheromone compounds is usually complex and costly. Camelina (Camelina sativa) has emerged as an ideal, non-food biotech oilseed platform for production of oils with modified fatty acid compositions. We used Camelina as a plant factory to produce mono- and di-unsaturated C12 chain length moth sex pheromone precursors, (E)-9-dodecenoic acid and (E,E)-8,10-dodecadienoic acid, by introducing a fatty acyl-ACP thioesterase FatB gene UcTE from California bay laurel (Umbellularia californica) and a bifunctional ∆9 desaturase gene Cpo_CPRQ from the codling moth, Cydia pomonella. Different transgene combinations were investigated for increasing pheromone precursor yield. The most productive Camelina line was engineered with a vector that contained one copy of UcTE and the viral suppressor protein encoding P19 transgenes and three copies of Cpo_CPRQ transgene. The T2 generation of this line produced 9.4% of (E)-9-dodecenoic acid and 5.5% of (E,E)-8,10-dodecadienoic acid of the total fatty acids, and seeds were selected to advance top-performing lines to homozygosity. In the T4 generation, production levels of (E)-9-dodecenoic acid and (E,E)-8,10-dodecadienoic acid remained stable. The diene acid together with other seed fatty acids were converted into corresponding alcohols, and the bioactivity of the plant-derived codlemone was confirmed by GC-EAD and a flight tunnel assay. Trapping in orchards and home gardens confirmed significant and specific attraction of C. pomonella males to the plant-derived codlemone.
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| 49. |
- Xia, Yi Han, et al.
(författare)
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Production of moth sex pheromone precursors in Nicotiana spp. : a worthwhile new approach to pest control
- 2020
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Ingår i: Journal of Pest Science. - : Springer Science and Business Media LLC. - 1612-4758 .- 1612-4766. ; 93:4, s. 1333-1346
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Tidskriftsartikel (refereegranskat)abstract
- Pheromones are environmentally friendly alternatives to traditional pesticides for pest control. They are widely applied for insect monitoring, mating disruption and mass trapping. Nicotiana benthamiana and N. tabacum are potential green biomass production platforms of moth sex pheromones. Using these two Nicotiana species as plant factories, we expressed biosynthetic genes of plant and insect origin in leaf tissue. Moth sex pheromone precursors (E)-11-tetradecenoic acid, (Z)-11-tetradecenoic acid and (Z)-11-hexadecenoic acid were produced by introducing the acyl-ACP thioesterases CpuFatB1 from Cuphea pulcherrima or CpaFatB2 from C. palustris and the fatty acyl desaturases Ave∆11 from Argyrotaenia velutinana, CpaE11 from Choristoneura parallela or Atr∆11 from Amyelois transitella, under the control of CaMV-35S promoter. Among the Nicotiana spp. transformants, the best line produced (Z)-11-hexadecenoic acid at 17.6% of total fatty acids in leaves, during flowering stage, corresponding to 335 µg of (Z)-11-hexadecenoic acid per gram of fresh leaf. The (Z)-11-hexadecenoic acid production lines from N. benthamiana were selected for further propagation to obtain homozygous lines. In the N. benthamiana T2 generation, the production quantity of (Z)-11-hexadecenoic acid was stable. Our study demonstrates the feasibility of stable transformation of N. benthamiana for production of moth pheromone precursors in vegetative tissue.
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| 50. |
- Xia, Yihan, 1990, et al.
(författare)
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Production of Moth Sex Pheromone Precursors in Nicotiana spp. by Agrobacterium-mediated Stable Transformation.
- 2020
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Ingår i: Journal of Pest Science. - : Springer Science and Business Media LLC. - 1612-4758 .- 1612-4766. ; 93:4, s. 1333-1346
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Tidskriftsartikel (refereegranskat)abstract
- Pheromones are environmentally friendly alternatives to traditional pesticides for pest control. They are widely applied for insect monitoring, mating disruption and mass trapping. Nicotiana benthamiana and N. tabacum are potential green biomass production platforms of moth sex pheromones. Using these two Nicotiana species as plant factories, we expressed biosynthetic genes of plant and insect origin in leaf tissue. Moth sex pheromone precursors (E)-11-tetradecenoic acid, (Z)-11-tetradecenoic acid and (Z)-11-hexadecenoic acid were produced by introducing the acyl-ACP thioesterases CpuFatB1 from Cuphea pulcherrima or CpaFatB2 from C. palustris and the fatty acyl desaturases Ave∆11 from Argyrotaenia velutinana, CpaE11 from Choristoneura parallela or Atr∆11 from Amyelois transitella, under the control of CaMV-35S promoter. Among the Nicotiana spp. transformants, the best line produced (Z)-11-hexadecenoic acid at 17.6% of total fatty acids in leaves, during flowering stage, corresponding to 335 µg of (Z)-11-hexadecenoic acid per gram of fresh leaf. The (Z)-11-hexadecenoic acid production lines from N. benthamiana were selected for further propagation to obtain homozygous lines. In the N. benthamiana T2 generation, the production quantity of (Z)-11-hexadecenoic acid was stable. Our study demonstrates the feasibility of stable transformation of N. benthamiana for production of moth pheromone precursors in vegetative tissue.
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